[mirror_ubuntu-focal-kernel.git] / fs / ext4 / xattr.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
  File: fs/ext4/xattr.h

  On-disk format of extended attributes for the ext4 filesystem.

  (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
*/

#include <linux/xattr.h>

/* Magic value in attribute blocks */
#define EXT4_XATTR_MAGIC		0xEA020000

/* Maximum number of references to one attribute block */
#define EXT4_XATTR_REFCOUNT_MAX		1024

/* Name indexes */
#define EXT4_XATTR_INDEX_USER			1
#define EXT4_XATTR_INDEX_POSIX_ACL_ACCESS	2
#define EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT	3
#define EXT4_XATTR_INDEX_TRUSTED		4
#define	EXT4_XATTR_INDEX_LUSTRE			5
#define EXT4_XATTR_INDEX_SECURITY	        6
#define EXT4_XATTR_INDEX_SYSTEM			7
#define EXT4_XATTR_INDEX_RICHACL		8
#define EXT4_XATTR_INDEX_ENCRYPTION		9
#define EXT4_XATTR_INDEX_HURD			10 /* Reserved for Hurd */

struct ext4_xattr_header {
	__le32	h_magic;	/* magic number for identification */
	__le32	h_refcount;	/* reference count */
	__le32	h_blocks;	/* number of disk blocks used */
	__le32	h_hash;		/* hash value of all attributes */
	__le32	h_checksum;	/* crc32c(uuid+id+xattrblock) */
				/* id = inum if refcount=1, blknum otherwise */
	__u32	h_reserved[3];	/* zero right now */
};

struct ext4_xattr_ibody_header {
	__le32	h_magic;	/* magic number for identification */
};

struct ext4_xattr_entry {
	__u8	e_name_len;	/* length of name */
	__u8	e_name_index;	/* attribute name index */
	__le16	e_value_offs;	/* offset in disk block of value */
	__le32	e_value_inum;	/* inode in which the value is stored */
	__le32	e_value_size;	/* size of attribute value */
	__le32	e_hash;		/* hash value of name and value */
	char	e_name[0];	/* attribute name */
};

#define EXT4_XATTR_PAD_BITS		2
#define EXT4_XATTR_PAD		(1<<EXT4_XATTR_PAD_BITS)
#define EXT4_XATTR_ROUND		(EXT4_XATTR_PAD-1)
#define EXT4_XATTR_LEN(name_len) \
	(((name_len) + EXT4_XATTR_ROUND + \
	sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND)
#define EXT4_XATTR_NEXT(entry) \
	((struct ext4_xattr_entry *)( \
	 (char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len)))
#define EXT4_XATTR_SIZE(size) \
	(((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND)

#define IHDR(inode, raw_inode) \
	((struct ext4_xattr_ibody_header *) \
		((void *)raw_inode + \
		EXT4_GOOD_OLD_INODE_SIZE + \
		EXT4_I(inode)->i_extra_isize))
#define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))

/*
 * The minimum size of EA value when you start storing it in an external inode
 * size of block - size of header - size of 1 entry - 4 null bytes
*/
#define EXT4_XATTR_MIN_LARGE_EA_SIZE(b)					\
	((b) - EXT4_XATTR_LEN(3) - sizeof(struct ext4_xattr_header) - 4)

#define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data))
#define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr))
#define BFIRST(bh) ENTRY(BHDR(bh)+1)
#define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)

#define EXT4_ZERO_XATTR_VALUE ((void *)-1)

struct ext4_xattr_info {
	const char *name;
	const void *value;
	size_t value_len;
	int name_index;
	int in_inode;
};

struct ext4_xattr_search {
	struct ext4_xattr_entry *first;
	void *base;
	void *end;
	struct ext4_xattr_entry *here;
	int not_found;
};

struct ext4_xattr_ibody_find {
	struct ext4_xattr_search s;
	struct ext4_iloc iloc;
};

struct ext4_xattr_inode_array {
	unsigned int count;		/* # of used items in the array */
	struct inode *inodes[0];
};

extern const struct xattr_handler ext4_xattr_user_handler;
extern const struct xattr_handler ext4_xattr_trusted_handler;
extern const struct xattr_handler ext4_xattr_security_handler;

#define EXT4_XATTR_NAME_ENCRYPTION_CONTEXT "c"

/*
 * The EXT4_STATE_NO_EXPAND is overloaded and used for two purposes.
 * The first is to signal that there the inline xattrs and data are
 * taking up so much space that we might as well not keep trying to
 * expand it.  The second is that xattr_sem is taken for writing, so
 * we shouldn't try to recurse into the inode expansion.  For this
 * second case, we need to make sure that we take save and restore the
 * NO_EXPAND state flag appropriately.
 */
static inline void ext4_write_lock_xattr(struct inode *inode, int *save)
{
	down_write(&EXT4_I(inode)->xattr_sem);
	*save = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND);
	ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
}

static inline int ext4_write_trylock_xattr(struct inode *inode, int *save)
{
	if (down_write_trylock(&EXT4_I(inode)->xattr_sem) == 0)
		return 0;
	*save = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND);
	ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
	return 1;
}

static inline void ext4_write_unlock_xattr(struct inode *inode, int *save)
{
	if (*save == 0)
		ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
	up_write(&EXT4_I(inode)->xattr_sem);
}

extern ssize_t ext4_listxattr(struct dentry *, char *, size_t);

extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t);
extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
extern int ext4_xattr_set_credits(struct inode *inode, size_t value_len,
				  bool is_create, int *credits);
extern int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode,
				struct buffer_head *block_bh, size_t value_len,
				bool is_create);

extern int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
				   struct ext4_xattr_inode_array **array,
				   int extra_credits);
extern void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *array);

extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
			    struct ext4_inode *raw_inode, handle_t *handle);

extern const struct xattr_handler *ext4_xattr_handlers[];

extern int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
				 struct ext4_xattr_ibody_find *is);
extern int ext4_xattr_ibody_get(struct inode *inode, int name_index,
				const char *name,
				void *buffer, size_t buffer_size);
extern int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode,
				       struct ext4_xattr_info *i,
				       struct ext4_xattr_ibody_find *is);

extern struct mb_cache *ext4_xattr_create_cache(void);
extern void ext4_xattr_destroy_cache(struct mb_cache *);

#ifdef CONFIG_EXT4_FS_SECURITY
extern int ext4_init_security(handle_t *handle, struct inode *inode,
			      struct inode *dir, const struct qstr *qstr);
#else
static inline int ext4_init_security(handle_t *handle, struct inode *inode,
				     struct inode *dir, const struct qstr *qstr)
{
	return 0;
}
#endif

#ifdef CONFIG_LOCKDEP
extern void ext4_xattr_inode_set_class(struct inode *ea_inode);
#else
static inline void ext4_xattr_inode_set_class(struct inode *ea_inode) { }
#endif

extern int ext4_get_inode_usage(struct inode *inode, qsize_t *usage);
Commit	Line	Data
	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	/*
	3	File: fs/ext4/xattr.h
	4
	5	On-disk format of extended attributes for the ext4 filesystem.
	6
	7	(C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
	8	*/
	9
	10	#include <linux/xattr.h>
	11
	12	/* Magic value in attribute blocks */
	13	#define EXT4_XATTR_MAGIC 0xEA020000
	14
	15	/* Maximum number of references to one attribute block */
	16	#define EXT4_XATTR_REFCOUNT_MAX 1024
	17
	18	/* Name indexes */
	19	#define EXT4_XATTR_INDEX_USER 1
	20	#define EXT4_XATTR_INDEX_POSIX_ACL_ACCESS 2
	21	#define EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT 3
	22	#define EXT4_XATTR_INDEX_TRUSTED 4
	23	#define EXT4_XATTR_INDEX_LUSTRE 5
	24	#define EXT4_XATTR_INDEX_SECURITY 6
	25	#define EXT4_XATTR_INDEX_SYSTEM 7
	26	#define EXT4_XATTR_INDEX_RICHACL 8
	27	#define EXT4_XATTR_INDEX_ENCRYPTION 9
	28	#define EXT4_XATTR_INDEX_HURD 10 /* Reserved for Hurd */
	29
	30	struct ext4_xattr_header {
	31	__le32 h_magic; /* magic number for identification */
	32	__le32 h_refcount; /* reference count */
	33	__le32 h_blocks; /* number of disk blocks used */
	34	__le32 h_hash; /* hash value of all attributes */
	35	__le32 h_checksum; /* crc32c(uuid+id+xattrblock) */
	36	/* id = inum if refcount=1, blknum otherwise */
	37	__u32 h_reserved[3]; /* zero right now */
	38	};
	39
	40	struct ext4_xattr_ibody_header {
	41	__le32 h_magic; /* magic number for identification */
	42	};
	43
	44	struct ext4_xattr_entry {
	45	__u8 e_name_len; /* length of name */
	46	__u8 e_name_index; /* attribute name index */
	47	__le16 e_value_offs; /* offset in disk block of value */
	48	__le32 e_value_inum; /* inode in which the value is stored */
	49	__le32 e_value_size; /* size of attribute value */
	50	__le32 e_hash; /* hash value of name and value */
	51	char e_name[0]; /* attribute name */
	52	};
	53
	54	#define EXT4_XATTR_PAD_BITS 2
	55	#define EXT4_XATTR_PAD (1<<EXT4_XATTR_PAD_BITS)
	56	#define EXT4_XATTR_ROUND (EXT4_XATTR_PAD-1)
	57	#define EXT4_XATTR_LEN(name_len) \
	58	(((name_len) + EXT4_XATTR_ROUND + \
	59	sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND)
	60	#define EXT4_XATTR_NEXT(entry) \
	61	((struct ext4_xattr_entry *)( \
	62	(char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len)))
	63	#define EXT4_XATTR_SIZE(size) \
	64	(((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND)
	65
	66	#define IHDR(inode, raw_inode) \
	67	((struct ext4_xattr_ibody_header *) \
	68	((void *)raw_inode + \
	69	EXT4_GOOD_OLD_INODE_SIZE + \
	70	EXT4_I(inode)->i_extra_isize))
	71	#define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))
	72
	73	/*
	74	* The minimum size of EA value when you start storing it in an external inode
	75	* size of block - size of header - size of 1 entry - 4 null bytes
	76	*/
	77	#define EXT4_XATTR_MIN_LARGE_EA_SIZE(b) \
	78	((b) - EXT4_XATTR_LEN(3) - sizeof(struct ext4_xattr_header) - 4)
	79
	80	#define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data))
	81	#define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr))
	82	#define BFIRST(bh) ENTRY(BHDR(bh)+1)
	83	#define IS_LAST_ENTRY(entry) ((__u32 )(entry) == 0)
	84
	85	#define EXT4_ZERO_XATTR_VALUE ((void *)-1)
	86
	87	struct ext4_xattr_info {
	88	const char *name;
	89	const void *value;
	90	size_t value_len;
	91	int name_index;
	92	int in_inode;
	93	};
	94
	95	struct ext4_xattr_search {
	96	struct ext4_xattr_entry *first;
	97	void *base;
	98	void *end;
	99	struct ext4_xattr_entry *here;
	100	int not_found;
	101	};
	102
	103	struct ext4_xattr_ibody_find {
	104	struct ext4_xattr_search s;
	105	struct ext4_iloc iloc;
	106	};
	107
	108	struct ext4_xattr_inode_array {
	109	unsigned int count; /* # of used items in the array */
	110	struct inode *inodes[0];
	111	};
	112
	113	extern const struct xattr_handler ext4_xattr_user_handler;
	114	extern const struct xattr_handler ext4_xattr_trusted_handler;
	115	extern const struct xattr_handler ext4_xattr_security_handler;
	116
	117	#define EXT4_XATTR_NAME_ENCRYPTION_CONTEXT "c"
	118
	119	/*
	120	* The EXT4_STATE_NO_EXPAND is overloaded and used for two purposes.
	121	* The first is to signal that there the inline xattrs and data are
	122	* taking up so much space that we might as well not keep trying to
	123	* expand it. The second is that xattr_sem is taken for writing, so
	124	* we shouldn't try to recurse into the inode expansion. For this
	125	* second case, we need to make sure that we take save and restore the
	126	* NO_EXPAND state flag appropriately.
	127	*/
	128	static inline void ext4_write_lock_xattr(struct inode inode, int save)
	129	{
	130	down_write(&EXT4_I(inode)->xattr_sem);
	131	*save = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND);
	132	ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
	133	}
	134
	135	static inline int ext4_write_trylock_xattr(struct inode inode, int save)
	136	{
	137	if (down_write_trylock(&EXT4_I(inode)->xattr_sem) == 0)
	138	return 0;
	139	*save = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND);
	140	ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
	141	return 1;
	142	}
	143
	144	static inline void ext4_write_unlock_xattr(struct inode inode, int save)
	145	{
	146	if (*save == 0)
	147	ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
	148	up_write(&EXT4_I(inode)->xattr_sem);
	149	}
	150
	151	extern ssize_t ext4_listxattr(struct dentry , char , size_t);
	152
	153	extern int ext4_xattr_get(struct inode , int, const char , void *, size_t);
	154	extern int ext4_xattr_set(struct inode , int, const char , const void *, size_t, int);
	155	extern int ext4_xattr_set_handle(handle_t , struct inode , int, const char , const void , size_t, int);
	156	extern int ext4_xattr_set_credits(struct inode *inode, size_t value_len,
	157	bool is_create, int *credits);
	158	extern int __ext4_xattr_set_credits(struct super_block sb, struct inode inode,
	159	struct buffer_head *block_bh, size_t value_len,
	160	bool is_create);
	161
	162	extern int ext4_xattr_delete_inode(handle_t handle, struct inode inode,
	163	struct ext4_xattr_inode_array **array,
	164	int extra_credits);
	165	extern void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *array);
	166
	167	extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
	168	struct ext4_inode raw_inode, handle_t handle);
	169
	170	extern const struct xattr_handler *ext4_xattr_handlers[];
	171
	172	extern int ext4_xattr_ibody_find(struct inode inode, struct ext4_xattr_info i,
	173	struct ext4_xattr_ibody_find *is);
	174	extern int ext4_xattr_ibody_get(struct inode *inode, int name_index,
	175	const char *name,
	176	void *buffer, size_t buffer_size);
	177	extern int ext4_xattr_ibody_inline_set(handle_t handle, struct inode inode,
	178	struct ext4_xattr_info *i,
	179	struct ext4_xattr_ibody_find *is);
	180
	181	extern struct mb_cache *ext4_xattr_create_cache(void);
	182	extern void ext4_xattr_destroy_cache(struct mb_cache *);
	183
	184	#ifdef CONFIG_EXT4_FS_SECURITY
	185	extern int ext4_init_security(handle_t handle, struct inode inode,
	186	struct inode dir, const struct qstr qstr);
	187	#else
	188	static inline int ext4_init_security(handle_t handle, struct inode inode,
	189	struct inode dir, const struct qstr qstr)
	190	{
	191	return 0;
	192	}
	193	#endif
	194
	195	#ifdef CONFIG_LOCKDEP
	196	extern void ext4_xattr_inode_set_class(struct inode *ea_inode);
	197	#else
	198	static inline void ext4_xattr_inode_set_class(struct inode *ea_inode) { }
	199	#endif
	200
	201	extern int ext4_get_inode_usage(struct inode inode, qsize_t usage);